Sifters and vibratory separators are used in a variety of applications for separating materials by size. For example, sifters and vibratory separators may be used to separate sized particles or to separate solids from liquids. These devices may be used to screen materials in various industries for industrial sorting, manufacturing operations, oil and gas drilling and production operations, etc.
Gyratory sifters are used in a variety of applications for separating solids by size. These applications include separating particles of sugar, flour, sand and various chemical powders. Gyratory sifters may be used for both wet and dry screening. Gyratory sifters include screens or perforated plates oriented generally horizontally, sloping from the head end (feed end) to the tail end (discharge end) of the sifter. The screens may be disposed in a screen basket. The screen basket may be suspended by a set of hangers that allow the basket to move on a horizontal plane. An eccentric drive mechanism, e.g., a belt driven eccentric weight, or other motive force is coupled to the screen basket to provide a circular motion substantially in a horizontal plane.
Generally, sifters include a class of vibratory devices used to separate sized particles, as well as to separate solids from liquids. Sifters are used to screen, for example, feed material, plastic resins, and powders during industrial sorting and/or manufacturing operations. Screens of sifterm include a perforated plate base or a ballbox upon which a wire mesh, or other perforated filter overlay, is positioned. The perforated plate base or ballbox generally provides structural support and allows the passage of fluids or sized material therethrough, while the wire mesh overlay defines the largest solid particle capable of passing therethrough.
Beneath the screens is a fines pan which collects fines. Fines are the sized material which has passed through the filter screen. The fines are discharged out the discharge end of the sifter alongside, but separated from, the product. Multiple cut machines have decks in series or parallel. Screens used with sifters are placed in a generally horizontal fashion on a substantially horizontal bed or support structure located within a basket in the sifter. The screens themselves may be flat, nearly flat, corrugated, depressed, and/or contain raised surfaces. The basket in which the screens are mounted may be inclined towards a discharge end of the sifter. The sifter imparts a rapidly reciprocating motion to the basket and the screens. A source material, from which particles are to be separated, is poured onto a back end of the screen. The material generally flows toward the discharge end of the basket. Large particles that are unable to pass through the screen remain on top of the screen, and move toward the discharge end of the basket where they are collected. Smaller particles and/or fluid pass through the screen and collect in a bed, receptacle, or pan therebeneath.
The frame of the sifter or screen basket is resiliently suspended or mounted upon a support. A circular or elliptical motion is imparted to the screen basket by rotating an unbalanced weight about a drive shaft connected to the frame.